The present invention relates generally to cooling a motor and, more specifically, to a method and apparatus for efficiently cooling a motor without mixing hot outlet gases with cool inlet gases.
Turbines, engines, and motors generate heat due to high-speed rotational motion. The generated heat may cause damage to a motor, for example, by severely burning the motor coil. Additionally, excess heat may damage the motor bearings. Thus, it is necessary that generated heat must be discharged.
In a typical motor, cooling air is moved through the motor or bearing to provide cooling. Typically, air is introduced in an axial direction and air exits in a radial direction. Axial introduction of air usually involves blowing hot air over the bearing, causing heating of the bearing. To protect the bearing, diverter plates may be used to isolate the bearing from heat. The hot air may be diverted around the bearing before exiting the motor as outlet air. However, the inlet air is introduced through the same region as the outlet air. This causes the hot inlet air to mix with the cooler outlet air. As heat from the hot inlet air is transferred to the cooler outlet air, the achieved temperature differential is lessened. Consequently, the amount of heat actually removed from the inlet air is less than ideal.
As can be seen, there is a need for an improved apparatus and method for cooling a motor to provide for bearing isolation, efficient cooling, and avoiding mixing inlet air with outlet air.